Re: Do I Need two batteries?
I say no, one battery is plenty. One deep cycle battery will have more capacity than a starting battery and a standard trolling battery. Not to mention as was stated before, you can pull start a 35.
One thing I seriously doubt most people who say to use two batteries have had is EXPERIENCE with running a single battery. I switched over to one battery in 2006 and haven't looked back since. It was one of the smartest moves I could have made. And here's why:
I have practically the same boat you do and my boat ran noticeably faster (not to mention I had a lot more room in the boat) when I got rid of the trolling battery up front and went to a single heavy duty deep cycle in the back. I also bought myself about an inch and a half of freeboard by getting rid of that battery and if fishing at rest and a large wave comes, having all the batteries in the world won't help if they cause your boat to swamp on you. My boat has had fewer waves break over the bow since removing that battery. Anything helps in a small boat! I've gone fishing with the trolling motor on "constant on" for 3-4 hours and when I touch the key it still makes the engine jump off the back of the boat. Deep cycles will also last longer and take more abuse.
I have a depth finder with a voltmeter as part of the display. At rest, my deep cycle shows 12.8 volts under no load when leaving the dock to go fishing. After 3-4 hours of trolling, at rest, it was 12.65 volts. That is still considered a fully charged battery!!!
No, you don't need 2 batteries. Having 2 is just a false sense of security because if something goes wrong, your starting battery will give you less power than your deep cycle will. But I guess to some people a false sense of security beats NO sense of security. How much energy do these people think it takes to start an engine with the touch of a key? A 35 at that? Almost zero! You would LONG notice your battery becoming sluggish with the trolling motor before you hit a level that wouldn't start a 35. Some of these responses, while well intended, don't take "small boat and engine" into consideration.
If I had a boat with more than 35ft lb of thrust trolling motor and larger than say a 40-50hp, I would suggest two batteries, but for small boats like ours, no, a single large heavy duty deep cycle is all that is needed.
